Andrew Carson

Underwater Face Mask

Diving mask using rebreather technology

Many divers are looking for ways to maximise the time they can spend underwater. Rebreather systems currently allow a dive duration of over 4 hours, however, the user often experiences stress and anxiety, resulting in faster breathing and consumption of air. This means that the user is the least efficient part of the system. Current re-breathers feature a full-face mask with an additional bite piece, reducing the volume of rebreathed dead space. The result of this is that the user is unaware of the elevating stress levels as the jaw applies a larger force onto the rubber bite piece. The body's natural senses
do not inform the user of a rise in stress. For this reason this project's aim was to resolve these user-centered problems by reducing stress.
Focus on the breathing loop began with the design of a robust mechanism to couple the breathing loop to the mask. This means that the user is not using their air supply whilst above the surface. However, a coupling method increases the risk of disengagement underwater when in panic meaning that the method of disengagement needed to be counter intuitive to prevent accidental uncoupling.
The second focus was to remove the bite piece seen in the current market. With a combination of theoretical, simulation and physical testing a nosecup has been designed with sufficient volume to reduce the amount of rebreathed CO2 as well as managing the work of breathing during the respiratory cycle.
The resulting physical prototype showed success early on in meeting the requirements of the relevant standard while improving the experience of the diver to deliver reduced stress and increasing performance.